Intra-uterine contraceptive

ABSTRACT

An intra-uterine contraceptive device is provided to fit the parturient uterus and gradually accommodate the involutionary process in a predetermined manner. The device is contractable in self-tracking manner by longitudinally progressive sliding engagement of one end of an elongate flexible member in the other end thereof. More particularly such a device is formed by a suitably dimensioned tapered tube.

i United States Patent [151 3,659,597

Wolfers [4 1 May 2, 1972 [54] INTRA-UTERINE CONTRACEPTIVE [56] em-mm Cited UNITED STATES PATENTS [72] Inventor: David Wolfers, London, England 3,353,533 11/1967 lshlhama ..128/l30 Asslgnw National Research Development p 3,407,806 10/1968 Hulka et al. ..12s 130 tion, London, England 22 Filed; 9 19 9 Primary Examiner-Lawrence Charles Attorney-Cushman, Darby & Cushman [21] App]. No.: 883,449

[57] ABSTRACT [30] Ford n A cation Prior Data An intra-uterine contraceptive device is provided to fit the 8 pp y parturient uterus and gradually accommodate the involutiona- Dec. 11, 1968 Great Britain ..58,969/68 ry process in a predetermined manner. The device is contractable in self-tracking manner by longitudinally progressive Cl sliding engagement of one end of an elongate flexible member in the other end thereof. More particularly such a device is [58] Field Of Search 1 30 fo -med by a suitably dimensioned tapered tube 13 Claims, 5 Drawing Figures IN'IRA-UTERINE CONTRACEPTIVE This invention relates to an inu'a-uterine contraceptive. An

object of the invention is to provide an intra-uterine conb. A decision to adopt contraception, if itsimplementation is deferred, is, as often as not, never'acted upon. This applies particularly to uneducated women and those hampered in their freedom of movement by large families.

c. A psychological effect of labor and delivery is a heighten-- ing of suggestibility and feelings of dependence, which favor acceptance of contraceptive service.

d. It is possible to establish contraception as a part ofroutine post-natal care.

While these advantages apply to any form of contraception, they are specially applicable to inter-uterine contraception because the single facilitated decision taken at delivery is semi-permanent in its effects. If therefore the insertion of an intra-uterine device at the time of delivery became routine, the problems of maintenance, supply, and continued motivation could be obviated.

Present intra-uterine devices have been used, although not extensively, for insertion immediately after delivery, butsufi'er from the disadvantage of very high expulsion rates (20 40 percent) and distortion of their shape.

These disadvantages are undoubtedly attributable to the disparity in size between the parturient uterus and the device which is designed to fit the involuted uterus.

In a more general aspect the present invention provides an intra-uterine contraceptive device adapted to fit the parturient uterus and gradually accommodate the involutionary process in predetermined manner.

In another more particular aspect, the invention provides-an intra-uterine contraceptive device comprising an elongate flexible member adapted to afford contraction by longitudinally progressive sliding engagement of 'one endof the member with the other end thereof along a spiral locus.

The longitudinal axis'of the device willlie along a coiled or convoluted path at any one time, be it a circular, spiral, helical or similar path. However, whatever the more particular shape of this path, the one end of the device necessarily follows a spiral locus as the device contracts with progressive engagement, the term spiral being used in its more general mathematical sense here.

It will be appreciated that such a device is particularly suited to manufacture in a size and shape for insertion to abut the lateral walls and fundus of the parturient uterus, while the sliding engagement allows contraction of the device under the action of, and thereby accommodating, the subsequent involuntary process.

It is preferred that the device be stressed or otherwise elastically formed to tend to adopt, when free of external restraints, an open form relative to the contracted form which can be obtained by the sliding engagement. The device will then, when inserted, tend to assume the correct size in any stage of uterine evolution.

Preferably, the member is slotted, notched, apertured, or otherwise formed to allow the escape of any undesirable fluids, such as unclotted blood, when the device assumes a contracted form in use.

Also, it may be preferred to provide the member with a latching arrangement which is actuated by initial sliding engagement between the two ends of the device, and which arrangement is thereafter effective to inhibit complete disengagement of the ends.

In order that the invention may be more clearly understood, the same will now be described, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 illustrates one fonn of device accordingto the invention in longitudinal section and with its ends disengaged,

FIG. Zsimilarly illustrates the device of FIG. 1 with its ends engaged,

FIG; 3 illustrates-thecross section found the device of FIG. 1, p

FIG. 4 illustrates the samedevice loaded in-an introducer, and

FIG. 5 illustrates a form of extractor suitable for use with the device of FIG. 1.

The-illustrated device consists of a tapered tube 10'of flexible plastics-material formed to adopt when free, an open loop or spiral shape as shown in FIG. 1. The wall thickness of the tube 10is small relative to the maximum diameter of the tube, and the inner periphery of the tube relative to the. spiral shaping has a continuousslot 11 which extends transversely. over about a quarter of the tube circumference. The tube material may be a soft silicon rubber, for example, but there are other well-known plasticsmaterials suitable for the present purpose. The material should, in any case, be such asto afford surfacesforthe tube having a relatively low coeificient of friction.

In the present. case, the narrower end 12 of the tube 11 is provided with a notch 13 engageable by a tongue provided in the wider end 15 of the tube.

In use of thedevice, the narrower end 12' of the tube is inserted in the wider end 15 and the notch 13 rides over the tongue 14 so that the. device can be contracted by. coiling as indicated by FIG. 2." In order to introduce the device into the uterine cavity, the device is loaded in partly or wholly contracted form into an introducer 16 comprising a flexible tube 17 and a piston 18 therein, as shown inFIG. 4, the loaded endof the introducer is insertedinto the cavity and the piston is operated to eject the contracted device into the cavity. When ejected, the device will expand to. abut the lateral walls and fundus of the uterus, but will contract with minimum resistance to accommodate uterine involution and will thereatterrespond to any periodic orirregular changes in the dimensions of the uterine cavity.

The device, once inserted, can be removed easily. by use of an extractor such as is shown: in FIG. 5,.withoutthe necessity of cervical dilation. The extractor of FIG. fi isof a well-known type and consists simply of a bent. rod with ahook 19' at one end. lfthe hook is of the kind having a latch 20, then. it may. be. unnecessary to have a latching arrangement, as is constituted by the notch. 13 and' tongue 14, provided in the contraceptive device. The main purpose of the latter arrangement is to prevent the device becoming'completely uncoiled and slipping out of the extractor during removal. The latch of the device can be regardedas having asecondary role to stop disengagement of the two ends of the device at other times, but the possibility of disengagement, once the device is engaged, will in fact only normally arise during removal. Thus the device will normally be engaged and contracted, and then immediately loaded into an introducer, the device being of such a size that the possibility of disengagement in the uterine cavity does not normally occur.

In this last connection, it isto be noted that the device is capable of introduction into the uterus at a very early stage of the puerperium and should preferably be inserted after the completion of the third stage of labor. For this purpose, the device should be dimensioned to provide, when engaged, a spiral form of about 3 inches maximum overall diameter permitting contraction to a minimum overall diameter of not more than 1 inch. In the case of a tapered tube such as that illustrated, this requirement is met by a tube of about 9 inches length capable of progressive sliding engagement through approximately three convolutions. Should a smaller size of device be required for use at a slightly later stage of the puerperium, this could conveniently provide a maximum overall diameter of 2 inches.

More generally speaking, the wall thickness and lumen should be dimensioned to permit at least two convolutions during contraction, with the wider end of the device being up together with convergence of the tube, or be of uniform thickness as shown. Also, the narrower end of the device may be solid.

It will, of course, be appreciated that a device according to the invention can equally well be employed for insertion other than during the puerperium, and a yet smaller size providing a maximum overall diameter of about 1% 1% inches can be provided for this purpose.

Following the last remarks above regarding sizes, it is to be noted that these are in the most part equally relevant to other I devices within the broader aspects of the present invention for which the illustrated form is only one example.

I claim:

1. An intra-uterine contraceptive device comprising an elongate flexible member adapted to afford contraction by longitudinally progressive sliding engagement of one end of the member with the other end thereof along a spiral locus; said member being stressed or otherwise elastically formed to tend to adopt an open form relative to its engaged contracted form; said member being slotted, notched, apertured or otherwise formed to permit the passage of fluid transversely therethrough when the device is engaged in said spiral form.

2. An intra-uterine contraceptive device comprising an elongate flexible member adapted to aflord contraction by longitudinally progressive sliding engagement of one end of the member with the other end thereof along a spiral locus; said member being provided with latching means actuated by said sliding engagement and effective to inhibit complete disengagement of the ends of said member.

3. An intra-uterine contraceptive device comprising an elongate flexible member adapted to afford contraction by longitudinally progressive sliding engagement of one end of the member with the other end thereof along a spiral locus; said member comprising a tapered tube the narrower end of which is slidably engageable in the wider end.

4. A device according to claim 3 wherein said tube has a continuous slot along its inner periphery relative to said con tracted form.

5. A device according to claim 4 wherein said slot extends transversely over about one quarter of the circumference of said tube.

6. A device according to claim 3 wherein said tube is provided with a notch at its narrower end and a tongue at its wider to 95 inch outside diameter. The wall thickness may decrease end to latch the former end when engaged in the latter end.

7. An intra-uterine contraceptive device comprising an elongate flexible member having a portion thereof leading from and including one end in mutual longitudinal sliding engagement encompassed within anotherportion thereof leading from and including the other end thereof to define a closed loop overall configuration, said loop being stressed to adopt an expanded open form and contractable against said stressby progressive increase of the length of said sliding engagement.

8. The device of claim 7, dimensioned to provide, when engaged, a maximum overall diameter of about 3 inches contractable by progressive sliding engagement to a minimum overall diameter of not more than i inch.

9. The device of claim 7 loaded in contracted form into one end of an introducer comprising a flexible tube having a piston translatable therethrough to eject said device.

10. A device according to claim 7 wherein said member is slotted, notched, apertured or otherwise formed to permit the passage of fluid transversely therethrough when the device is contracted.

11. An intra-uterine contraceptive device comprising an elongate resiliently flexible element of split-ring shaped transverse cross-sectional shape and split-ring shaped appearance in elevation, the element thus having two opposite ends; the transverse cross-section of said element graduating in ring-size from one end toward the other; the smaller radiussed of said ends being so much smaller than the radius of the transverse cross section of the element at the other end thereof, that the former is insertable into the latter for telescoping the device,

convolute-fashion.

12. A device according to claim 11 wherein the change in radius of the cross section of the device in proceeding from said one end toward said other end thereof is sufficient to permit at least two complete convolutions of the device, that is, an angular separation of said two ends of at least 720".

13; An intra-uterine contraceptive device comprising an elongate resiliently flexible member of generally loop-shape, 

1. An intra-uterine contraceptive device comprising an elongate flexible member adapted to afford contraction by longitudinally progressive sliding engagement of one end of the member with the other end thereof along a spiral locus; said member being stressed or otherwise elastically formed to tend to adopt an open form relative to its engaged contracted form; said member being slotted, notched, apertured or otherwise formed to permit the passage of fluid transversely therethrough when the device is engaged in said spiral form.
 2. An intra-uterine contraceptive device comprising an elongate flexible member adapted to afford contraction by longitudinally progressive sliding engagement of one end of the member with the other end thereof along a spiral locus; said member being provided with latching means actuated by said sliding engagement and effective to inhibit complete disengagement of the ends of said member.
 3. An intra-uterine contraceptive device comprising an elongate flexible member adapted to afford contraction by longitudinally progressive sliding engagement of one end of the member with the other end thereof along a spiral locus; said member comprising a tapered tube the narrower end of which is slidably engageable in the wider end.
 4. A device according to claim 3 wherein said tube has a continuous slot along its inner periphery relative to said contracted form.
 5. A device according to claim 4 wherein said slot extends transversely over about one quarter of the circumference of said tube.
 6. A device according to claim 3 wherein said tube is provided with a notch at its narrower end and a tongue at its wider end to latch the former end when engaged in the latter end.
 7. An intra-uterine contraceptive device comprising an elongate flexible member having a portion thereof leading from and including one end in mutual longitudinal sliding engagement encompassed within another portion thereof leading from and including the other end thereof to define a closed loop overall configuration, said loop being stressed to adopt an expanded open form and contractable against said stress by progressive increase of the length of said sliding engagement.
 8. The device of claim 7, dimensioned to provide, when engagEd, a maximum overall diameter of about 3 inches contractable by progressive sliding engagement to a minimum overall diameter of not more than 1 inch.
 9. The device of claim 7 loaded in contracted form into one end of an introducer comprising a flexible tube having a piston translatable therethrough to eject said device.
 10. A device according to claim 7 wherein said member is slotted, notched, apertured or otherwise formed to permit the passage of fluid transversely therethrough when the device is contracted.
 11. An intra-uterine contraceptive device comprising an elongate resiliently flexible element of split-ring shaped transverse cross-sectional shape and split-ring shaped appearance in elevation, the element thus having two opposite ends; the transverse cross-section of said element graduating in ring-size from one end toward the other; the smaller radiussed of said ends being so much smaller than the radius of the transverse cross section of the element at the other end thereof, that the former is insertable into the latter for telescoping the device, convolute-fashion.
 12. A device according to claim 11 wherein the change in radius of the cross section of the device in proceeding from said one end toward said other end thereof is sufficient to permit at least two complete convolutions of the device, that is, an angular separation of said two ends of at least 720*.
 13. An intra-uterine contraceptive device comprising an elongate resiliently flexible member of generally loop-shape, which, in an unstressed state, proceeds through more than 360*; said member having one end thereof configured to accept and slidably guidingly engage a portion of said member leading from and including the other end thereof, telescoping fashion, so that as said loop is compressively stressed in a sense to decrease the circumference of the loop, the accepted, other end tracks the loop in a circumferential direction. 